(PHP 5 >= 5.1.2, PECL hash >= 1.1)
hash_final — Finalize an incremental hash and return resulting digest
Hashing context returned by hash_init().
When set to TRUE, outputs raw binary data. FALSE outputs lowercase hexits.
Returns a string containing the calculated message digest as lowercase hexits unless raw_output is set to true in which case the raw binary representation of the message digest is returned.
Example #1 hash_final() example 以上例程会输出：
<?php
$ctx = hash_init('sha1');
hash_update($ctx, 'The quick brown fox jumped over the lazy dog.');
echo hash_final($ctx);
?>
c0854fb9fb03c41cce3802cb0d220529e6eef94e